Mechanical structures interacting with high-temperature gases, such as jet engine exhaust systems, the exterior surfaces of hypersonic aircraft, and furnace liners, may be composed of a metal component providing strength, and coated with, e.g., a ceramic coating to provide thermal protection, preventing the metal component from being weakened by heating. In such an application, a coating with low thermal conductivity may be desirable, to reduce heat flow into the metal component.
Certain related art ceramic coatings, such as 7 wt % yttria-stabilized zirconia thermal barrier coatings (TBCs) have a thermal conductivity in the range of 0.8-1.6 W/mK (Watts per meter-Kelvin) at room temperature. Such a coating may be applied utilizing either a plasma spray process or an electron-beam physical vapor deposition process, which may result in a porosity of 10-20%. A lower thermal conductivity would be beneficial. Related art TBCs focus on protecting metal components, but are not well compatible with ceramic components due to their different coefficient of thermal expansion.
Thus, there is a need for a system and method of providing improved thermal and environmental protection for ceramic components exposed to high-temperature gases.